Nasal interface and system including ventilation insert

ABSTRACT

A ventilation or CPAP interface system adapted to be inserted into a nares of a user to secure the interface. A cannula adapted to be connected to a source of ventilation gas forms a first portion of an input gas flow passage to supply the ventilation gas to the user. A nasal insert adapted to be inserted the nares of the user forms a second portion of the input gas flow passage from the cannula to a distal end of the nasal insert. A seal portion adapted to engage a portion of the first naris is provided adjacent the distal end of the nasal insert. Ventilation interface system may optionally include feed tubes, y-connector, tube holder, headgear and a headgear flange.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation-in-Part of co-pending applicationSer. No. 10/658,769, filed on Sep. 10, 2003, the entire contents ofwhich are hereby incorporated by reference and for which priority isclaimed under 35 U.S.C. §120.

This application is related in subject matter to U.S. Pat. No.6,478,026, PCT patent application No. PCT/US03/24590, filed Aug. 6,2003, U.S. patent application Ser. Nos. 10/610,594 filed Jul. 2, 2003,10/044,925 filed Jan. 15, 2002, 10/096,795 filed Mar. 14, 2002, and10/392,959 filed Mar. 21, 2003, all to Thomas J. Wood, the disclosuresof which are incorporated by reference herein in their entirety.

BACKGROUND OF THE INVENTION

1. FIELD OF THE INVENTION

Exemplary embodiments of the invention are directed to a ventilationinterface, and more particularly to a ventilation interface including acannula forming a first portion of an input gas flow passage and a nasalinsert forming a second portion of the input gas flow passage, the firstand second portions of the input gas flow passage disposed at an obtuseangle to one another.

2. DISCUSSION OF RELATED ART

Obstructive sleep apnea syndrome (commonly referred to as obstructivesleep apnea, sleep apnea syndrome, and/or sleep apnea) is a medicalcondition characterized by repeated, prolonged episodes of cessation ofbreathing during sleep. During a period of wakefulness, the muscles ofthe upper part of the throat passage of an individual keep the passageopen, thereby permitting an adequate amount of oxygen to flow into thelungs. During sleep, the throat passage is narrowed due to therelaxation of the muscles. In those individuals having a relativelynormally sized throat passage, the narrowed throat passage remains openenough to continue to permit the adequate amount of oxygen to flow intothe lungs. However, in those individuals having a relatively smallersized throat passage, the narrowed throat passage prohibits the adequateamount of oxygen from flowing into the lungs. Additionally, one or moreof a nasal obstruction, a relatively large tongue, and/or certain shapesof the palate and/or the jaw of the individual further prohibit theadequate amount of oxygen from flowing into the lungs.

The individual having the above-discussed conditions can stop breathingfor one or more prolonged periods of time (e.g., each period of timebeing 10 seconds or more). The prolonged periods of time during whichbreathing is stopped, or apneas, are generally followed by suddenreflexive attempts to breathe. The reflexive attempts to breathe aregenerally accompanied by a change from a relatively deeper stage ofsleep to a relatively lighter stage of sleep. As a result, theindividual suffering from obstructive sleep apnea syndrome generallyexperiences fragmented sleep that is not restful. The fragmented sleepresults in one or more of excessive and/or inappropriate daytimedrowsiness, headache, weight gain or loss, limited attention span,memory loss, poor judgment, personality changes, lethargy, inability tomaintain concentration, and/or depression.

Other medical conditions can also prevent individuals, including adultsand infants, from receiving the adequate amount of oxygen into thelungs. For example, an infant who is born prematurely can have lungsthat are not developed to an extent necessary to receive the adequateamount of oxygen. Further, prior to, during, and/or subsequent tocertain medical procedures and/or medical treatments, an individual canbe unable to receive the adequate amount of oxygen.

Under these circumstances, it is known to use a ventilation interface toapply a positive pressure to the throat of the individual, therebypermitting the adequate amount of oxygen to flow into the lungs. In theknown ventilation interface, oxygen and/or room air containing oxygen isdelivered through the mouth and/or nose of the individual. Known typesof positive pressure applied by the known ventilation interface includecontinuous positive airway pressure (CPAP) in which a positive pressureis maintained in the throat passage throughout a respiratory cycle,bilevel positive airway pressure (BiPAP) in which a relatively highpositive pressure is maintained during inspiration and a relatively lowpositive pressure is maintained during expiration, and intermittentmechanical positive pressure ventilation (IPPV) in which a positivepressure is applied when apnea is sensed (i.e., the positive airwaypressure is applied intermittently or non-continuously).

A known ventilation interface for the application of such positivepressures includes a conventional face mask that covers the nose and/ormouth, as well as a conventional pair of nasal pillows that are insertedinto corresponding nares of the naris.

The conventional face mask requires a harness, such as a headband and/orother headgear components, to provide and maintain a required fluid orgas tight seal between the mask and the face of the individual.Additionally, the conventional tubing will collapse if it is bent aroundthe ears with the flat side against the side of the users head. Thus,the use of such a conventional harness and tubing results in a number ofdisadvantages.

For example, because pressure must be applied between the requiredharness and the head of the individual to maintain the required seal,the harness is generally uncomfortable, particularly when sleeping. Theapplied pressure often results in undesirable irritation and sorescaused by movement of the mask and harness during periods of bothwakefulness and sleep. Further, the required seal is generally unable tobe maintained when the mask and harness is moved. The mask alsogenerally applies an undesirable pressure to the sinus area that isadjacent to the nose, causing the nasal sinus airways to narrow, therebyincreasing a velocity of flow through the upper anatomical airways anddecreasing lateral pressure against the nasal mucosal walls. Further,the tubing may fold undesirably further exacerbating the above problem.The above-discussed combination of increased flow velocity and decreasedpressure results in the removal of moisture from the mucosal wallsduring inspiration, causing an undesirable drying and a burningsensation within the nares. As a result, the individual may remove themask to alleviate these discomforts, consequently discontinuing thebeneficial application of the positive pressure.

The conventional nasal pillows include pillowed style nasal seals thatare pressed against the bottom portion of the nares. However, the knownnasal pillows also require the use of a harness to keep the nasalpillows pressed against the bottom of the nares, resulting indisadvantages similar to those of the conventional face mask.

For these reasons, it is desirable to provide a nasal interface andsystem that overcomes one or more of the above-discussed disadvantages.

SUMMARY OF THE INVENTION

Exemplary embodiments of the present invention provide a ventilationinterface adapted to be inserted into a nares of a user to secure theinterface. A cannula adapted to be connected to a source of ventilationgas forms a first portion of an input gas flow passage to supply theventilation gas to the user. A nasal insert adapted to be inserted intothe nares of the user forms a second portion of the input gas flowpassage from the cannula to a distal end of the nasal insert. A sealportion adapted to engage a portion of the first nares can be providedadjacent the distal end of the nasal insert. The first and secondportions of the input gas flow passage are disposed at an obtuse angleto one another.

In another exemplary embodiment of the invention, a gas output forms aportion of an output gas flow passage from the nasal insert to anexterior of the ventilation interface to channel a gas expired by theuser. Optionally, the second portion of the input gas flow passage andthe portion of the output gas flow passage can be configured to providelaminar flow therebetween.

In yet another exemplary embodiment, the seal portion of the nasalinsert forms a seal with the naris of the user by optionally aresiliency of the seal portion of the nasal insert or a resiliency ofthe nares of the user or some combination of the two. Further, at leastone of the nasal insert and the seal portion may, optionally, besufficiently flexible to be expanded by a positive pressure provided bythe ventilation gas to help form a seal portion.

Exemplary embodiments of the present invention further provide aventilation interface adapted to be inserted into a nares of a userwhich can secure the interface. A first subassembly forms a firstportion of an input gas flow passage from a ventilation gas supplysource. A second subassembly forms a second portion of the input gasflow passage from the first subassembly to a first naris of the nares ofthe user. A subassembly for engaging a portion of the first naris isprovided on the second subassembly. The first and second portions of theinput gas flow passage are disposed at an obtuse angle to one another.

Exemplary embodiments of the present invention further provide a feedtube and y-connector adapted for use in a ventilation interface system.The feed tube having an annular sleeve and may optionally include afirst exterior portion and a second exterior portion; the first exteriorportion including a plurality of first ribs and a second exteriorportion including a plurality of second ribs.

Yet further exemplary embodiments of the present invention provide aventilation interface system including a cannula adapted to be connectedto a source of ventilation gas via a feed tube and a y-connector, thecannula forming a first portion of an input gas flow passage to supplythe ventilation gas to the user. A nasal insert adapted to be insertedthe nares of the user, the nasal insert forming a second portion of theinput gas flow passage from the cannula to a distal end of the nasalinsert. A seal portion adapted to engage at least a portion of the naresof the user, the seal portion provided adjacent the distal end of thenasal insert wherein the first and second portions of the input gas flowpassage are disposed at an obtuse angle to one another. Optionally, heador harness gear may be provided to assist in holding the nasal insertsin place.

In another exemplary embodiment, the headgear's interaction with theheadgear flange may hold the nasal inserts in the nares of a user.Further, a thin skirt may optionally be wrapped around the ridges of thenasal insert and may assist in preventing leaks.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the exemplary embodiments of the presentinvention, and one or more of the attendant advantages thereof, will bereadily ascertained and/or obtained as the same becomes betterunderstood by reference to the following detailed description whenconsidered in connection with the accompanying drawings, wherein:

FIG. 1 shows an exploded side elevation view of a first exemplaryembodiment of the ventilation interface system.

FIG. 2 shows a side elevation view of a ventilation insert.

FIG. 3 shows a side view of the ventilation insert of FIG. 2.

FIG. 4 shows a top view of the ventilation insert of FIG. 2.

FIG. 5 shows a side view of the ventilation insert of FIG. 2.

FIG. 6 shows a cross-sectional view taken from line I-I in FIG. 3.

FIG. 7 shows an elevated side view of an oval feed tube.

FIG. 8 shows a cross-sectional view of a feed tube taken along lineII-II in FIG. 7.

FIG. 9 shows a cross-sectional view of the oval feed tube of FIG. 7.

FIG. 10 shows a side view of a round feed tube.

FIG. 11 shows a cross-section of the round feed tube of FIG. 10.

FIG. 12 shows a cross-sectional view of the round feed tube of FIG. 9.

FIG. 13 shows a side elevation view of an exemplary embodiment of aventilation insert.

FIG. 14 shows a side view of the ventilation insert of FIG. 13

FIG. 15 shows a side view of the ventilation insert of FIG. 13.

FIG. 16 shows a top view of the ventilation insert of FIG. 13

FIG. 17 shows a bottom view of the ventilation insert of FIG. 13

FIG. 18 shows a cross sectional view along the line IV-IV of FIG. 13

FIG. 19 shows a cross sectional view along the line V-V of FIG. 16.

FIG. 20 shows a cross sectional view along the line VI-VI of FIG. 16.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Examples of one or more exemplary embodiments of the present inventionwill now be described with reference to the drawings, wherein likereference numbers throughout the several views identify like and/orsimilar elements.

Generally referring to FIGS. 1-20, exemplary embodiments of the presentinvention can provide a ventilation interface system adapted to beinserted into a nares of a user to secure the interface. A cannula 300adaptable to be connected to a source of ventilation gas (not shown)forms a first portion 141 of an input gas flow passage to supply theventilation gas to the user. Nasal inserts 120 are adapted to beinserted into the nares of the user forms a second portion 123 of theinput gas flow passage from the cannula to a distal end of the nasalinsert 130. A seal portion 122 optionally adapted to engage a portion ofthe nares of the user is positioned at the distal end 130 of the nasalinsert. The first 141 and second portions 123 of the input gas flowpassage may be disposed at an obtuse angle to one another.

In another exemplary embodiment of the invention, the obtuse angle isbetween about 110° and about 170°, and more preferably the obtuse angleis about 135°.

In a further exemplary embodiment of the invention, gas output flowpassages 150, form a portion of an output gas flow passage from thenasal insert 120 to an exterior of the ventilation interface to channela gas expired by the user. Optionally, the second portion 123 of theinput gas flow passage formed by the nasal insert is about parallel withthe portion of the output gas flow passage 150. Moreover, the secondportion 123 of the input gas flow passage and the portion of the outputgas flow passage 150 are configured to, optionally, provide laminar flowtherebetween.

In yet another exemplary embodiment, the nasal inserts 120, and the sealportions 122 form a seal with the nares of the user by, optionally, aresiliency of the seal portion 122 and nasal insert 120 or a resiliencyof the nares of the user or some combination of the above with aheadgear 700 assisting in gently holding the nasal insert 120 into thenares. Alternatively, the headgear 700 may be configured to be attachedto headgear flange 800, 801. Further, at least one of the nasal inserts120 and the seal portions 122 may, optionally, be sufficiently flexibleto be expanded by a positive pressure provided by the ventilation gas tohelp form a seal with the nares of the user. Additionally, a skirt 180may be attached to the portion 122 of the nasal insert 120 to preventleakage.

Specifically, as shown in the FIGS. 1-20 exemplary embodiments of aventilation interface 100 of the present invention can include, amongother components, a cannula 300, nasal inserts 120, seal portions 122and gas outputs 150, to be described below.

The cannula 300 can be adapted to be connected to a source ofventilation gas (not shown), such as oxygen and/or room air containingoxygen, to apply a positive pressure to the throat of the user of theventilation interface 100, thereby permitting an adequate amount ofoxygen to flow into the lungs. Optionally, the system may be connectedto a mechanical ventilator. Although the figures show certain exemplaryembodiments of the cannula 300, it is to be understood that the cannula300 can be of any type, so long as the cannula 300 can be connected tothe source of the ventilation gas.

The cannula 300 can include a distal end 142 connectable to the sourceof the ventilation gas via a feed tube 500, 600. In an exemplaryembodiment of the invention, the y-connector 703 can include an exteriorsurface and an interior surface defining a wall portion therebetween,each of the exterior and interior surfaces having optionallysubstantially circular or oval cross section. By this arrangement, they-connector 703 can be connected with the source of the ventilation gasat one end and to the feed tube at the other end 500, 600.

The cannula 300 can include a cannula body 303 adjacent to distal end142 that defines a first portion 141 of the input gas flow passage, andmore specifically can define the second portion 123 of the input gasflow passage through the cannula body 303. The cannula body 303 candefine a portion of an output gas flow passage, and, more specifically,can define the fourth portion 153 of the output gas flow passage fromthe nasal insert 120 through the cannula body 303 (discussed below). Thecannula body 303 can extend along one or more axes such that laminarflow can be achieved within the second portion 123 of the input gas flowpassage and/or such that laminar flow can be achieved within the fourthportion 153 of the output gas flow passage. Further, the cannula body303 can extend along the one or more axes such that laminar flow can beachieved between the second portion 123 of the input gas flow passageand portions of the input gas flow passage upstream and/or downstream ofthe second portion, and/or can extend along the one or more axes suchthat laminar flow can be achieved between the fourth portions 153 andthe second portions 123 of the output gas flow passage. Optionally,portions of the axes of the second portion 123 of the input gas flowpassage and/or the fourth portion 153 of the output gas flow passageextend along a substantially arcuate line.

The nasal insert 120 can be disposed adjacent the cannula body 303 andcan be adapted to be inserted the nares of the user to apply thepositive pressure to the throat of the user. Although the figures showcertain exemplary embodiments of the nasal insert 120, it is to beunderstood that the nasal insert 120 can be of any type, so long thenasal insert 120 can be inserted into the nares to apply the positivepressure.

The nasal insert 120 can define a third portion 305 and a fourth portion153 of the input gas flow passage, and more specifically can define thethird 305 and fourth 153 portions of the input gas flow passage from thecannula 300 through the nasal insert 120. The nasal insert 120 candefine a second portion 123 and a third portion 305 of the output gasflow passage, and more specifically can define the second 123 and third305 portions of the output gas flow passage from the sealing portion 122through the nasal insert 120. In an exemplary embodiment of theinvention, the nasal insert 120 can include an exterior surface and aninterior surface defining a wall portion therebetween, each of theexterior and interior surfaces may have a varying cross sectionincluding oval shapes or, optionally, substantially circular or flatshapes, such that the nasal inserts 120 can define the above-identifiedflow passages.

The nasal insert 120 can have a maximum interior cross sectional areaand circumference at a proximal end 121 of the nasal insert 120 that isadjacent the cannula 300, thereby defining the third portion 305 of theinput/output gas flow passage. The nasal insert 120 may optionally havea minimal interior cross sectional area and circumference at a distalend 130 of the nasal insert 120 that is disposed away from the cannula300 (i.e., opposite the proximal end 121), thereby defining the fourthportion 153 of the input/output gas flow passage, and thereby definingthe second portion 123 of the input/output gas flow passage. Optionally,the nasal insert 120 may have the substantially same interior crosssectional area and circumference at the distal 130 and proximal ends121. In an exemplary embodiment of the invention, the proximal end 121may, optionally, be in the form of an ellipse, oval or circle and thedistal end 122 can be in the form of an ellipse, oval or circle.

The nasal insert 120 can extend along an axis such that laminar flow canbe achieved within and/or between the third 305 and fourth portions 153of the input/output gas flow passage, and/or within and/or between thesecond 123 and third 305 portions of the output gas flow passage.Further, the nasal insert 120 can extend along the axis such thatlaminar flow can be achieved among the third 305 and fourth 153 portionsof the input/output gas flow passage and portions of the input gas flowpassage upstream and/or downstream of the third 305 and fourth 153portions, and/or such that laminar flow can be achieved among the secondand third portions of the output gas flow passage and portions of theoutput gas flow passage upstream and/or downstream of the second 123 andthird 305 portions.

The seal portion 122 can be disposed adjacent the distal end 130 of thenasal insert 120, and can be adapted to engage the interior portion ofthe user's nares to thereby retain the ventilation interface 100therewithin. Although the figures show certain exemplary embodiments ofthe seal portion 122, it is to be understood that the seal portion 122can be of any type, so long as the seal portion 122 can engage theinterior portion of the nares.

In yet another exemplary embodiment of the invention, the seal portion122 can include an exterior surface and an interior surface defining awall portion therebetween, each of the exterior and interior surfacesmay have an about C-shaped or arcuate surface and having a circular oroval cross section, such that the seal portion 122 can define theabove-identified flow passages. An interior portion of the seal portion122 can have an interior cross section in the form of an ellipse, oralternatively can have one or both of an interior surface and anexterior surface with an about tear-shaped or optionally a circularcross-section.

In another exemplary embodiment of the invention, the maximum interiorcross section and its corresponding circumference may, optionally, begreater than the interior cross section and circumference of the distalend 130 of the nasal insert 120. A maximum exterior cross section andits corresponding circumference of the seal portion 122 may optionallybe greater than the exterior cross section and circumference of thedistal end 130.

The seal portion 122 and/or the nasal insert 120 can include an elasticmaterial, the resiliency of which may retain the first ventilationinterface 100 in the nares. Further, the seal portion 122 and/or thenasal insert 120 can optionally be expanded by the positive pressure ofthe ventilation gas, thereby aiding in the retention of the firstventilation interface 100 within the nares. Optionally, the nasal insert120 need not deform when entering the user's nares.

The seal portion 122 can extend along an axis such that laminar flow canbe achieved within the fifth portion 152 of the input gas flow passage,and/or within the first portion of the output gas flow passage. Further,the seal portion 122 can extend along the axis such that laminar flowcan be achieved between the fifth 152 portion of the input gas flowpassage and upstream of the input gas flow passage, and/or such thatlaminar flow can be achieved between the first 141 portion of the outputgas flow passage and downstream of the output gas flow passage.Optionally, the axis is substantially a straight line.

The gas output 150 can be disposed adjacent the cannula body 303opposite to the nasal insert 120, and can be adapted to channel the gasexpired by the user to the exterior of the ventilation interface.Although the figures show certain exemplary embodiments of the gasoutput 150, it is to be understood that the gas output 150 can be of anytype, so long as the gas output 150 can channel the gas expired by theuser to an exterior of the ventilation interface 100.

The gas output 150 can define a fifth portion 152 of the output gas flowpassage, and more specifically can define the fifth 152 of the outputgas flow passage from the cannula body 303 through the gas output. In anexemplary embodiment of the invention, the gas output 150 can include anexterior surface and an interior surface defining a wall portiontherebetween, each of the exterior and interior surfaces having avarying cross section including circular shapes, such that the gasoutput 150 can define the above-identified flow passages. The gas output150 can have a maximum interior cross sectional area and circumferenceat a proximal end 141 of the gas output 150 that is adjacent the cannulabody 303, thereby defining the fifth 152 portion of the output gas flowpassage. The gas output 150 can have a minimal interior cross sectionalarea and circumference at a distal end 157 of the gas output 150 that isdisposed away from the cannula body 303 (i.e., opposite the proximal end141), thereby defining the fifth 152 portion of the output gas flowpassage.

In an exemplary embodiment, laminar flow is achieved among and/or withinone or more of the portions (i.e., the first through fifth portions) ofthe input gas flow passage of the first ventilation interface 100 isachieved among and within all of the portions of the input gas flowpassage.

Also as discussed above, the output gas flow passage can channel theexpired gas from the nares of the user of the ventilation interface 100,and more specifically can channel the expired gas from of the nares ofthe user to and through the first portion of the sealing portion 122, toand through the third 305 portion of the distal end 122 of the nasalinsert 120, to and through the second 123 portion of the proximal end121 of the nasal insert 120, to and through the fourth 153 portion ofthe cannula body 303 of the cannula 300, to and through the fifth 152portion of the gas output 150, to the exterior of the ventilationinterface 100. In an exemplary embodiment of the invention, laminar flowis achieved among and/or within each of the portions (i.e., the firstthrough fifth portions) of the output gas flow passage of theventilation interface 100, and more optionally is achieved among andwithin all the portions of the output gas flow passage.

A ventilation interface 100 according to exemplary embodiments of thepresent invention can avoid disadvantages of the known or conventionalventilation interface requiring a harness.

Referring generally to FIGS. 7-12. In yet another exemplary embodimentof the present invention, the oval feed tubing 500 provides an ovalcross-section 505. The distance 503 between the ribs 501 at the bottomsurface shorten when bent and the distance between the ribs 504 on thetop 502 surface of the tubing wall lengthens in order for the tubing tobend without decreasing the cross-sectional area of the tube. This alsogives the oval tubing 500 the ability to drape around the ears of auser. Optionally, circular tubing 600, with a circular cross-sectionalare 602, provides ribs 601 which can be bent around the ears.

In FIG. 9, the distance between the bottom ribs 503 are spaced when thetubing is straight. When draped in a radius position the distancebetween the lower ribs 503 is closed and the wall shortens withoutcausing spring-back tension. The points between the top ribs 500 simplyseparate further at the top when the tube is bent, but not the bottomribs 503 where the wall thickness is very thin. In between each point ofthe 500 area there is a slight bend of the thin wall. The accumulationof the sum of each bend gives the radius at the top of the tubing. Theaccumulation of the compression of the spaces at 503 gives the tubingits radius at the bottom.

Thus, the ventilation interface system according to the exemplaryembodiments of the present invention can provide the ventilation gasfrom the ventilation source to the nares at a lower velocity as comparedto the conventional ventilation interface, thereby decreasing an amountof moisture removed from the mucosal walls. Further the ventilationinterface system provides better comfort and functionality over theknown conventional systems.

Generally referring to FIGS. 13-20 the headgear 700 may be configured tobe attached to headgear flange 800, 801. The interaction between theheadgear 700 and the headgear flange 800, 801 may hold the nasal insertsin the nares of the user.

Numerous additional modifications and variations of the exemplaryembodiments present invention are possible in light of the aboveteachings. It is therefore to be understood that within the scope of theappended claims, exemplary embodiments of the present invention may bepracticed otherwise than as specifically described herein.

1. A ventilation interface configured to be inserted into a nares of auser to secure the interface, comprising: a cannula with at least onenasal insert and at least one exhaust port; the cannula forming a firstportion of an input gas flow passage to supply the ventilation gas; thenasal insert configured to be inserted into a first naris of the naresof the user, the nasal insert forming second and third portions of theinput gas flow passage from the cannula to a distal end of the nasalinsert; a seal portion configured to engage at least a portion of thenares, the seal portion being provided on the distal end of the at leastone nasal insert; and at least one headgear flange disposed the cannulabody.
 2. The ventilation interface according to claim 1, wherein thefirst, second and third portions of the inflow passage are disposed atan obtuse angle which is between about 110° and about 170°.
 3. Theventilation interface according to claim 1 wherein the headgear flangeis configured to receive a headgear strap which holds the nasal insertin place.
 4. The ventilation interface according to claim 1, wherein theproximal end of the nasal insert forms a second portion of the input gasflow passage having a substantially oval cross section.
 5. Theventilation interface according to claim 4, wherein a distal end of thenasal insert forms a third portion of the input gas flow passage havinga substantially oval cross section.
 6. The ventilation interfaceaccording to claim 5, wherein the third portion of the input gas flowpassage has a circumference that is less than a circumference of thesecond portion of the input gas flow passage.
 7. The ventilationinterface according to claim 6, wherein the seal portion forms a thirdportion of the input gas flow passage having a substantially oval crosssection.
 8. The ventilation interface according to claim 7, wherein thedistal end of the nasal insert includes a first exterior portion havinga substantially oval cross section.
 9. The ventilation interfaceaccording to claim 8, wherein the portion of the nasal insert proximalthe cannula includes a second exterior portion having a substantiallyoval cross section.
 10. The ventilation interface according to claim 9,wherein the first exterior portion has a circumference that is less thana circumference of the second exterior portion.
 11. The ventilationinterface according to claim 10, wherein the seal portion includes athird exterior portion having at least one of a substantially oval crosssection or a round cross section.
 12. The ventilation interfaceaccording to claim 11, wherein the third exterior portion has acircumference that is larger than the circumference of the secondexterior portion.
 13. The ventilation interface according to claim 11,wherein the third exterior portion has a circumference that issubstantially equal to the circumference of the second exterior portion.14. The ventilation interface according to claim 1, further comprising:a gas output forming a portion of an output gas flow passage from thenasal insert to an exterior of the ventilation interface to channel agas expired by the user.
 15. The ventilation interface according toclaim 14, wherein the second portion of the input gas flow passageformed by the nasal insert is about parallel with the portion of theoutput gas flow passage.
 16. The ventilation interface according toclaim 15, wherein the second portion of the input gas flow passage andthe portion of the output gas flow passage are configured to providelaminar flow therebetween.
 17. The ventilation interface according toclaim 16, wherein a distal end of the gas output forms a first portionof the output gas flow passage having a substantially circular crosssection.
 18. The ventilation interface according to claim 17, wherein aportion of the gas output proximal the cannula forms a second portion ofthe output gas flow passage having a substantially circular crosssection.
 19. The ventilation interface according to claim 18, whereinthe first portion of the output gas flow passage has a circumferencethat is less than a circumference of the second portion of the outputgas flow passage.
 20. The ventilation interface according to claim 1,wherein at least one of the nasal insert and the seal portion issufficiently flexible to be expanded by a positive pressure provided bythe ventilation gas.
 21. The ventilation interface according to claim 1,wherein at least one of the nasal insert and the seal portion forms aseal with the nares of the user by at least one of deformation of atleast one of the nasal insert, the nares of the user, the seal portionor a headgear.
 22. The ventilation interface according to claim 1,wherein at least one of the nasal insert and the seal portion forms aseal with the nares of the user by friction between the nares of theuser and at least one of the nasal insert, the seal portion or aheadgear.
 23. The ventilation interface according to claim 1, wherein atleast one of the nasal inserts and the seal portion form a seal with atleast one naris of the user by a resiliency of at least one of said sealportion and said nares of the user and a headgear.
 24. A ventilation orCPAP interface system, comprising: a cannula, nasal inserts, sealportions and exhaust ports; feed tubes and a y-connector; a tubingconnector; head gear and at least one headgear flange; the cannula isadapted to be connected to a source of ventilation gas via the feedtubes and y-connector, the cannula forming a first portion of an inputgas flow passage to supply the ventilation gas to the user; the nasalinserts are adapted to be inserted into the nares of the user, the nasalinserts form a second portion of the input gas flow passage from thecannula to a distal end of the nasal inserts; and a seal portion adaptedto engage at least a portion of the nares, the seal portion providedadjacent a distal end of the nasal insert.
 25. The ventilation interfaceaccording to claim 24, wherein the headgear flange is configured toreceive a headgear strap which holds the nasal insert in place.